USB: serial: metro-usb: remove vendor and product module parameters

All new usb serial drivers should be using the dynamic id function, not
having module parameters for this type of thing.  So remove them before
anyone gets used to them being there.

Cc: Aleksey Babahin <tamerlan311@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>